How difficult to build a DIY Lithium Ion Battery Charger?

Click For Summary

Discussion Overview

The discussion revolves around the challenges and considerations involved in building a DIY lithium-ion battery charger. Participants explore the technical aspects, safety concerns, and available resources related to charging lithium-ion batteries.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants suggest that charging lithium-ion batteries is not particularly difficult, noting that it involves using a constant current until a specified voltage is reached, typically around 4.2V per cell.
  • Others mention the availability of integrated circuits (ICs), such as the National Semiconductor’s LM3622, which can simplify the charging process.
  • One participant points out that lithium-ion batteries with built-in charging and protection circuits are available, which may further simplify DIY projects.
  • Contrarily, a participant warns about the dangers of charging lithium-ion batteries, citing personal experience with an explosion, indicating significant safety concerns.
  • Another participant argues that charging lithium-ion batteries may be easier than charging nickel-metal hydride (NiMH) or nickel-cadmium (NiCad) batteries, suggesting that detecting the completion of charging is straightforward due to noticeable changes.

Areas of Agreement / Disagreement

Participants express differing views on the difficulty and safety of building a DIY lithium-ion battery charger. While some believe it is manageable with the right components, others emphasize the potential dangers involved, indicating that the discussion remains unresolved.

Contextual Notes

Participants reference specific charging methods and components, but there is no consensus on the overall safety and complexity of the DIY approach. The discussion reflects varying levels of experience and caution among participants.

Galteeth
Messages
69
Reaction score
1
Not asking for a schematic, more a notion of roughly how challenging this will be.
 
Physics news on Phys.org
I read a bit on wikipedia, and it doesn't seem that hard. You charge with a constant current which depends on the battery type until you hit a certain voltage according to the manufacturer's specs around 4.2V per cell, which you hold until there is almost no more current. Does that sound complicated to you? I am sure that there are already ICs available for common Li-battery types.
 
0xDEADBEEF said:
I read a bit on wikipedia, and it doesn't seem that hard. You charge with a constant current which depends on the battery type until you hit a certain voltage according to the manufacturer's specs around 4.2V per cell, which you hold until there is almost no more current. Does that sound complicated to you? I am sure that there are already ICs available for common Li-battery types.
National has a chip. Look up National Semiconductor’s LM3622 Li-Ion
Battery Charger Controller chip. See also
http://www.national.com/appbriefs/files/AppBrief101.pdf
for a USB-based lithium ion battery charger circuit.
Bob S
 
Last edited by a moderator:
Bob S said:
National has a chip. Look up National Semiconductor’s LM3622 Li-Ion
Battery Charger Controller chip. See also
http://www.national.com/appbriefs/files/AppBrief101.pdf
for a USB-based lithium ion battery charger circuit.
Bob S

Interesting thanks. With the chip it seems easy enough.
 
Last edited by a moderator:
Bob S said:
National has a chip. Look up National Semiconductor’s LM3622 Li-Ion
Battery Charger Controller chip. See also
http://www.national.com/appbriefs/files/AppBrief101.pdf
for a USB-based lithium ion battery charger circuit.
Bob S

And I would note that you can buy LI Ion batteries on the internet that have a charging/protection circuit built into the end of the battery (I think they are AA cells) which simplifies charging circuits.
 
Last edited by a moderator:
BAAADDD IDEA! Charging these beasts is dangerous as it is. I don't mean to be overcautious but I've had one explode in my backyard and it's very dangerous.
 
Charging these batteries is easier than charging NiMh or NiCad's. I think it would be farly straight farward to detect when charging is completed as there is a very noticable change.
 

Similar threads

Electronics DIY a wireless charger into a book
  • · Replies 4 ·
Replies
4
Views
4K
Safer Lithium Ion Batteries - a Significant Step
  • · Replies 1 ·
Replies
1
Views
1K
Undergrad How do I know the lithium content of a lithium-ion battery?
  • · Replies 13 ·
Replies
13
Views
4K
Lithium-Sulfur Batteries? Maybe
  • · Replies 2 ·
Replies
2
Views
2K
Misc. Looking for entry level DIY ideas
  • · Replies 3 ·
Replies
3
Views
3K
Li-Ion Battery Charger for Drill - 12V 3s Balance Charger
  • · Replies 1 ·
Replies
1
Views
2K
Manually charging batteries
  • · Replies 11 ·
Replies
11
Views
3K
Co-free, High-Energy, Fast-Charging, Long-Lasting Li-Ion Batteries?
  • · Replies 0 ·
Replies
0
Views
3K
Lithium-ion rechargeable batteries
  • · Replies 2 ·
Replies
2
Views
2K
Electrical Build a DIY Powerbank with NiMH Batteries: Guidelines & Tips
  • · Replies 12 ·
Replies
12
Views
7K